A pressure sensor is typically a device with a diaphragm which, when exposed to a pressure, deflects and causes that pressure sensor to output a signal associated with that pressure. Conventional pressure sensors may be used in a variety of applications, including pressure monitoring of a person's vitals. Conventional pressure monitoring may include intra-cranial pressure monitoring during neurosurgery, air pressure monitoring for respiratory diseases, blood pressure monitoring during surgery and/or intensive care, intra-uterine monitoring for obstetrics, as well as abdominal and/or urinary pressure monitoring for the diagnosis of various disorders. Typically, these measurements are made through noninvasive techniques or invasive techniques, such as through a catheter.
Catheters may include a pressure sensor that may be in turn configured extravascularly or intravascularly. When pressure sensors are configured intravascularly, they may be further configured at the tip of the catheter or on the side wall of the catheter. Side-wall pressure sensors typically have an advantage in measuring pressure in that the side-wall pressure sensor is often able to more accurately measure the normal pressure against the side-wall of the catheter as well as the momentum of the fluid as it moves around the catheter. However, conventional pressure sensors are often too large to be configured either as catheter-tipped pressure sensors or as side-wall pressure sensors.
Conventional catheters are often configured with their diameters corresponding to French units, where 1 French is equivalent to about ⅓ of a millimeter (e.g., 333 microns or 333 μm). As such, pressure sensors configured thereupon must be somewhat smaller. Conventional pressure sensors are often configured to utilize four terminals and may include a half-Wheatstone bridge design or a full-Wheatstone bridge design. However, since many catheters (e.g., including those that are 1 French or smaller) can only accommodate three lead wires (e.g., the smaller the catheter the less the number of lead wires that may be configured therein), conventional pressure sensors are generally unable to be fully configured to sense pressure associated therewith. Moreover, conventional pressure sensors often include two or more piezoresistors in various orientations, increasing fabrication costs (e.g., the time to fabricate, as well as the cost from the increased likelihood of lithographic alignment errors), the likelihood of components failing and/or otherwise increasing the overall size of conventional sensors.
Therefore, a need exists in the art for a pressure sensor that overcomes the aforementioned limitations in conventional designs.